Height-adjustable desk

ABSTRACT

A height-adjusting mechanism for a desk consisting of a support tube connected to the base of the desk, a sliding tube telescopically mounted with respect to the support tube and connected to the top of the desk and a lever-activated clamping tube located between the sliding and support tubes, said clamping tube having a clamping ring that engages and holds the sliding tube in place when the tube is in clamping position and that releases the sliding tube for adjustment when moved by the lever to its release position. Spring means are further provided for biasing the clamping tube toward clamping position.

United States Patent Goebl 1451 July 29, 1975 [54] HEIGHT-ADJUSTABLE DESK 2,702,6g 3/1952 g'iinlnis 248/412 2,72 ,l l 195 0c [761 ifg gg gggfx gggggjg 3,741,514 6/1973 Snurr 248/412 [22] Filed: June 8, 1973 Primary ExaminerRoy D. Frazier Assistant Examiner-Darrell Marquette [21] Appl' 368313 Attorney, Agent, or FirmFinnegan, Henderson,

Farabow and Garrett [30] Foreign Application Priority Data June 12, 1972 Switzerland 8689/72 ['57] ABSTRACT A height-adjusting mechanism for a desk consisting of [52] US. Cl. 108/146, 108/150, 234182721523, 3 pp tube connected to the base of the desk, a [51] Int Cl 2 A47B 9/08 sliding tube telescopically mounted with respect to the [58] Fieid 146 144 support tube and connected to the top of the desk and 5 a lever-activated clamping tube located between the 403/368 6 sliding and support tubes, said clamping tube having a clamping ring that engages and holds the sliding tube lace when the tube is in clamping position and that [56] References Clted m p releases the slldlng tube for ad ustment when moved UNITED STATES PATENTS by the lever to its release position. Spring means are 376,016 l/1888 Stuck 248/412 further provided for biasing the clamping tub t a d 1,075,323 10/1913 Benjamins..... 248/412 l i i i 1,103,839 7/1914 Rellay 248/412 1,238,423 8/1917 Matthey 248/412 5 Claims, 4 Drawing Figures HEIGHT-ADJUSTABLE DESK This invention relates to a height-adjustable desk, and more particularly to a new and improved heightadjusting mechanism for a desk that can be readily operated by a convenient, foot-operated lever.

With the present overcrowding of school rooms and the lack of adequate facilities, there has been more and more need to provide mobile equipment, and more particularly student desks or tables that can easily be adjusted to accommodate the height of the various users.

The present invention provides for such an adjustable desk comprising a base portion and a top portion supporting a desk or table that can be pulled up or pushed down and locked in place with respect to the base portion. A vertical support tube is connected to and extends upwardly from the base portion, and a sliding tube concentrically mounted for telescoping'movement with respect to the support tube is connected to and extends downwardly from the top portion of the desk. A clamping tube is located'between the sliding and support tubes and has limited movement between a release position and a clamping position. Clamping means are mounted on the clamping tube which are pressed into engagement with the sliding tube to hold it in place by friction when the clamping tube is in clamping'position and which are disengaged from the sliding tube when the clamping tube'is moved to the release position to permit the desk top to be raised or lowered. Spring means are further provided for biasing the clamping tube toward clamping position, and lever means are provided for moving the clamping tube against the spring means toward its release position. Preferably, the lever means are mounted on the base portion to provide a convenient foot-operated mechanism.

The accompanying drawings which are incorporated in and constitute a part of the specification illustrate an embodiment of the invention and together with the description serve to explain the principles of the invention.

Of the drawings:

FIG. 1 is a rear view of a double desk utilizing the height-adjusting mechanism of the present invention;

FIG. 2 is a side view of the desk shown in FIG. 1; and

FIG. 3 is an exploded view partially in section showing the height-adjusting mechanism of the present invention; and

FIG. 4 is a sectional view along the line 44 of FIG. 3.

With reference to FIG. 1, the base portion of the desk comprises a base tube 1 on whose ends are transversely mounted foot tubes 2 and 4 having rubber coasters 7 for supporting the desk in a stable manner. As this is a double desk, the base tube 1 supports two upright, vertical support tubes 3 into each of which are telescopically mounted vertical sliding tubes 20. Tubes are connected to a transverse member 21 having side parts 22 that support the top of the desk. The desk top may obviously be replaced by a table top or any other form of top without departing from the scope of the present invention.

As best shown in FIG. 3, the height-adjusting mechanism of the present invention includes support tube 3 and sliding tube 20 as well as a clamping tube 17 that is located between support tube 3 and sliding tube 20. Tube 17 has limited movement between a clamping position shown in solid in FIG. 3, where sliding tube 20 is gripped in place and a release position shown in phantom in FIG.- 3, where the sliding tube and the attached top portion of thedesk are free'to slide with respect to support tube 3.

In accordancewiththe invention, clamping means are provided for engagingth sliding tube to hold it in placewhen clamping tube 17 is in clamping position. As embodied and as shown in FIG. 3, the clamping means comprises an outer clamping ring 14 fixed to the open top of support tube 3 and held in place by screw or pin 16. The inside'of clamping ring 14 has a tapered bore. An inner clamping ring 18 having a complementary taper is also mounted to the upper end of clamping tube 17. When clamping tube 17 is in clamping position, as shown in FIG. 3, and the tapers of clamping rings 14 and 18 are brought into engagement with each other, the opposite side of clamping ring 18 is thus pushed into engagement with sliding tube 20 to hold it in place by friction and lock the desk top at the desired height.

' In accordance with the invention, spring means are also provided for biasing the clamping tube toward clamping position. As embodied, this spring means comprises a fixed stop 19 mounted to the periphery of clamping tube '17 and an annular spring 15 mounted between clamping ring l4 and stop 19 on the clamping tube. Spring 15 thus exerts a downward force on clamping tube 17 tending to draw clamping ring 18 into clamping ring 14 and against sliding tube 20. A guide pin 31 between sliding tube 20 and clamping tube 17 as well as the cylindrical inner surface of clamping ring 18 guides the vertical movement of sliding tube 20 and prevents play between the tube and clamping tube 17. A slot or other guide means for receipt of pin 31 may he provided, if desired, in sliding tube 20 to prevent the tube and the desk top from twisting with respect to the base portion.

In accordance with the invention, lever means are further provided for moving the clamping tube against spring 15 toward release position to release the grip of clamping ring 18 on sliding tube 20 so that the top portion of the desk can be adjusted to the desired height. As embodied and as shown in FIG. 3, this means comprises a lever arm 10 pivotally connected at one end to a foot-operated push-button 12 mounted in a collar 13 in base tube 1 by a pin 9 having a cross arm 9a engaging slot 27 between tips 10a of arm 10 as shown in FIGS. 3 and 4. Lever arm 10 has a flat 26 at the opposite end that extends through an opening 28 in the base of support tube 3 and engages a supporting ring 29 on the bottom of clamping tube 17 As best shown in FIG. 3, lever arm 10 pivots about a support pin 1 1 in base tube 1 and moves outwardly at the same time as button 12 is pushed down.

In operation and to change the height of the desk top, button 12 is pushed downwardly, for instance, by the foot to rotate lever arm 10 about pivot or fulcrum 11 and push clamping tube 17 upwardly against spring 15 toward its release position. As clamping tube 17 moves upwardly, clamping ring 18 attached to the top of the tube also moves upwardly out of engagement with fixed clamping ring 14 on tube 3 thereby releasing its grip on sliding tube 20 and permitting it to slide with respect to support tube 3. Then, with the foot still on button 12, the top portion of the desk is raised or lowered the desired height. Following adjustment, pressure on button 12 is released and spring 15 then pushes clamping tube l7 downwardly to bring the tapers of clamping rings 14 and 18 back into engagement with each other and. to push ring 18 against sliding tube 20 and lock the desk at the desired height.

By providing a desk having two vertical support tubes 3, any wrenching or twisting of the top portion with respect to the base portion is obviously prevented although a single mechanism for a single desk can also be used.

To prevent sliding tube 20 from being pushed down into engagement with the floor, the flat 26 on lever arm preferably extends beyond clamping ring 17 so that it will engage the bottom of sliding tube 20 and thereby limit the lowermost position of the tube.

It can readily be seen, therefore, that the mechanism of the present invention permits simple and rapid adjustment of a student desk or table without the use of any .tools and in an efficient and trouble-free manner.

The invention in its broader aspects is not limited to the specific details shown and described and departures may be made from such details without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

l. A height-adjustable desk comprising a base portion and a top portion, a pair of support tubes mounted on the base portion, a sliding tube concentrically mounted for telescoping movement with respect to each of the support tubes and connected to the top portion of the desk, a clamping tube located between said sliding and support tubes and mounted for movement between a clamping position and a release position, clamping means mounted on each of said clamping tubes for gripping the sliding tube to hold it in place when the clamping tube is in clamping position and for releasing the sliding tube when the clamping tube is in release position, spring means for biasing each of the clamping tubes toward clamping position, lever means for moving the clamping tubes toward release position so that the top portion can be adjusted to the desired height, said moving means comprising a pair of lever arms pivotally mounted on the base portion of the desk, each of said arms having a portion disposed to engage the associated clamping tube to push it upwardly and disengage the clamping means.

2. The desk of claim 1, wherein said lever arms simultaneously move the clamping tubes in the pair of support tubes.

3. The desk of claim 1 in which a pair of pivot pins is carried by said base portion,, and each lever arm engages a pivot pin intermediate the ends thereof whereby said pins act as fulcrum points.

4. The desk of claim 3 in which said other ends engage the clamping tubes and also form lower limits for the sliding tubes.

'5. The desk of claim 3 in which each support tube has an opening adjacent the bottom end thereof and said other end of the associated lever arm extends through said opening into engagement with the clamping tube. l 

1. A height-adjustable desk comprising a base portion and a top portion, a pair of support tubes mounted on the base portion, a sliding tube concentrically mounted for telescoping movement with respect to each of the support tubes and connected to the top portion of the desk, a clamping tube located between said sliding and support tubes and mounted for movement between a clamping position and a release position, clamping means mounted on each of said clamping tubes for gripping the sliding tube to hold it in place when the clamping tube is in clamping position and for releasing the sliding tube when the clamping tube is in release position, spring means for biasing each of the clamping tubes toward clamping position, lever means for moving the clamping tubes toward release position so that the top portion can be adjusted to the desired height, said moving means comprising a pair of lever arms pivotally mounted on the base portion of the desk, each of said arms having a portion disposed to engage the associated clamping tube to push it upwardly and disengage the clamping means.
 2. The desk of claim 1, wherein said lever arms simultaneously move the clamping tubes in the pair of support tubes.
 3. The desk of claim 1 in which a pair of pivot pins is carried by said base portion,, and each lever arm engages a pivot pin intermediate the ends thereof whereby said pins act as fulcrum points.
 4. The desk of claim 3 in which said other ends engage the clamping tubes and also form lower limits for the sliding tubes.
 5. The desk of claim 3 in which each support tube has an opening adjacent the bottom end thereof and said other end of the associated lever arm extends through said opening into engagement with the clamping tube. 